<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script>
			var i=Number("2");
			
			i=Number(null);//0
			i=Number(false);//0
			i=Number(true);//1
			i=Number("false");//NaN not a number
			alert(i)
		</script>
	</head>
	<body>
	</body>
</html>
